Recording/playback apparatus

ABSTRACT

This invention provides an apparatus capable of performing time slip playback even upon occurrence of a network trouble. This invention relates to an apparatus which, when a network trouble occurs, acquires, of multimedia data, a point representing the position of multimedia data which has already been transmitted to a network, and after the network recovers, transmits multimedia data subsequent to the point to the network.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 2002-020689, filed Jan.29, 2002, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a recording/playback apparatuscapable of playing back multimedia data while recording it.

[0004] 2. Description of the Related Art

[0005] New recording/playback systems have recently been developed.According to this system, a recording/playback apparatus and aninformation processing apparatus (e.g., personal computer, PDA, orportable telephone) are connected by a network. While recording digitalmedia data such as TV images, video images, or the like in a storagedevice (HDD, optical disk, or the like), the recording/playbackapparatus transmits the multimedia data to the information processingapparatus. The information processing apparatus plays back thetransmitted multimedia data.

[0006] The recording/playback system can issue an instruction as ofplayback, fast forward, rewind, or pause from the information processingapparatus to the recording/playback apparatus. The recording/playbackapparatus performs an operation based on an instruction from theinformation processing apparatus while recording digital media data.

[0007] When the information processing apparatus designates playback,the recording/playback apparatus plays back digital media data(transmits digital media data to the information processing apparatus)while recording it (time slip playback or time-shift playback).

[0008] If a trouble occurs in a network while the recording/playbackapparatus plays back digital media data, the recording/playbackapparatus stops time slip playback including recording of digital mediadata and transmission of the digital media data to the informationprocessing apparatus.

[0009] Even if the network recovers, the recording/playback apparatuskeeps stopping time slip playback including recording of digital mediadata and transmission of the digital media data to the informationprocessing apparatus. The recording/playback system cannot resume timeslip playback.

BRIEF SUMMARY OF THE INVENTION

[0010] The present invention has been made in consideration of the abovesituation, and has as its object to provide a recording/playbackapparatus capable of performing time slip playback even upon occurrenceof a network trouble.

[0011] To achieve the above objects, according to the present invention,there is provided a n apparatus which transmits multimedia data to beplayed back to a network, comprising: means for, when a trouble of thenetwork is detected, stopping transmission of the multimedia data; meansfor acquiring a point representing a position of the multimedia dataobtained when transmission of the multimedia data is stopped; and meansfor retransmitting the multimedia data to the network from the pointacquired by the acquiring means.

[0012] According to another aspect of the present invention, there isprovided an apparatus which transmits multimedia data to be played backto a network, comprising: means for transmitting the multimedia data tothe network; means for, when a trouble of the network is detected,stopping transmission of the multimedia data; means for acquiring apoint representing a position of the multimedia data obtained whentransmission of the multimedia data is stopped; means for transmittingthe point acquired by the acquiring means to the network on the basis ofa point acquisition request; and means for transmitting the multimediadata to the network on the basis of a multimedia data acquisitionrequest in response to the transmitted point.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0013]FIG. 1 is a view for explaining the use environment of arecording/playback system according to an embodiment of the presentinvention;

[0014]FIG. 2 is a block diagram showing the arrangement of arecording/playback apparatus;

[0015]FIG. 3 is a block diagram showing the arrangement of a PC;

[0016]FIG. 4 is a functional block diagram showing therecording/playback apparatus according to the embodiment of the presentinvention;

[0017]FIG. 5 is a flow chart for explaining the operation of therecording/playback apparatus according to the embodiment of the presentinvention;

[0018]FIG. 6 is a view for explaining the concept of time slip playback;

[0019]FIG. 7 is a functional block diagram showing a recording/playbackapparatus according to another embodiment of the present invention;

[0020]FIG. 8 is a functional block diagram showing the PC; and

[0021]FIG. 9 is a flow chart for explaining the operation of arecording/playback system including the recording/playback apparatusaccording to the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0022] A recording/playback system according to an embodiment of thepresent invention will be described below with reference to the severalviews of the accompanying drawing.

[0023]FIG. 1 is a view for explaining the use environment of therecording/playback system according to the embodiment of the presentinvention.

[0024] As shown in FIG. 1, a recording/playback apparatus 2 according tothe embodiment stores a television image received by a TV antenna 1 in astorage device 3 while transmitting the television image stored in thestorage device 3 to personal computers (to be referred to as PCshereinafter) 4 and 5 via a WLAN (Wireless Local Area Network) or LAN(Local Area Network) (time slip playback). The PCs 4 and 5 play back thetelevision image transmitted from the recording/playback apparatus 2,and instruct the recording/playback apparatus to perform fast forward,rewind, or pause.

[0025] The recording/playback apparatus 2 can be connected to avideocassette recorder 6, television 7, and the like. Therecording/playback apparatus 2 can also perform time slip playback of avideo image input from the videocassette recorder 6. Therecording/playback apparatus 2 can display a TV image received by the TVantenna 1 on the television 7.

[0026] The image is a television image in FIG. 1, but may be anymultimedia data such as audio data or video data. A device which playsback multimedia data transmitted from the recording/playback apparatusis not limited to a PC, and may be an information processing apparatussuch as a PDA (Personal Digital Assistant) or portable telephone.Examples of the storage device 3 are an HDD, optical disk, MO, andmemory card.

[0027]FIG. 2 is a block diagram showing the arrangement of therecording/playback apparatus. The same reference numerals as in FIG. 1denote the same parts.

[0028] As shown in FIG. 2, the recording/playback apparatus 2 comprisesan encoder 13, a decoder 17, a CPU 15, the storage device 3, a memory16, a LAN card interface 18, and a PC card interface 20, all of whichare connected to a bus 14.

[0029] The encoder 13 is connected to the TV antenna 1 via a decoder 12and TV tuner 11. The encoder 13 compresses and outputs TV image data(multimedia data) which is received by the TV antenna 1 and input viathe TV tuner 11 and decoder 12. The encoder 13 is, e.g., an MPEG2encoder.

[0030] The CPU 15 controls the whole recording/playback apparatus 2, andexecutes a program for implementing the operation of therecording/playback apparatus (to be described later).

[0031] The storage device 3 stores a resume point representing theposition (played-back position) of a multimedia data portion which hasbeen transmitted to the PC. The storage device 3 stores a program forimplementing the operation of the recording/playback apparatus.

[0032] The decoder 17 decodes multimedia data encoded by the encoder andoutputs the data to a video output terminal. The decoder 17 is, e.g., anMPEG2 decoder.

[0033] The memory 16 stores a program which is installed and is to beexecuted by the recording/playback apparatus. The memory 16 has variousarithmetic areas.

[0034] The LAN card interface 18 is an interface for connecting the bus14 and a LAN card 19. The PC card interface 20 is an interface forconnecting the bus 14 and a PC card wireless LAN 21. The LAN card 19communicates with a PC serving as a terminal via a network. The PC cardwireless LAN 21 communicates with a PC serving as a terminal via awireless network.

[0035]FIG. 3 is a block diagram showing the arrangement of the PC.

[0036] As shown in FIG. 3, the PC according to the embodiment of thepresent invention comprises a decoder 32, CPU 33, storage device 34,memory 35, LAN card interface 36, PC card interface 37, and displaycontroller 38, all of which are connected to a bus 31.

[0037] The decoder 32 decompresses multimedia data compressed by theencoder of the recording/playback apparatus. The decoder 32 is, e.g., anMPEG2 decoder.

[0038] The CPU 33 controls the overall PC, and executes a program forrealizing the operation of the PC (to be described later).

[0039] The storage device 34 stores multimedia data transmitted from thePC and a program for realizing the operation of the PC.

[0040] The memory 35 stores a program which is installed and is to beexecuted by the recording/playback apparatus. The memory 35 has variousarithmetic areas.

[0041] The LAN card interface 36 is an interface for connecting the bus31 and a LAN card 39. The PC card interface 37 is an interface forconnecting the bus 31 and a PC card wireless LAN 40. The LAN card 39communicates with a PC serving as a terminal via a network. The PC cardwireless LAN 40 communicates with a PC serving as a terminal via awireless network.

[0042] The display controller (DSC) 38 performs the entire displaycontrol, plays back multimedia data decompressed by the decoder 32, anddisplays the data on a display 41.

[0043]FIG. 4 is a functional block diagram showing therecording/playback apparatus according to the embodiment of the presentinvention.

[0044] As shown in FIG. 4, the recording/playback apparatus according tothe embodiment of the present invention comprises a network statedetecting unit 51, multimedia data recording unit 52, storage unit 53,resume point monitoring unit 54, resume point acquiring unit 55, resumepoint reading unit 56, multimedia data acquiring unit 57, and multimediadata transmitting unit 58.

[0045] The network state detecting unit 51 detects the network state ofa network connected to a PC. More specifically, the network statedetecting unit 51 detects a network trouble such as disconnection of thenetwork, or recovery of the network after occurrence of a networktrouble.

[0046] The multimedia data recording unit 52 stores in the storage unit53 multimedia data which is input to the recording/playback apparatusand compressed by the encoder.

[0047] The resume point monitoring unit 54 always monitors, ofmultimedia data stored in the storage unit 53, a resume pointrepresenting the position of a multimedia data portion which has beentransmitted to the PC. The resume point is expressed by the playbacktime from the header of a multimedia data file, the file size, or thelike.

[0048] The resume point acquiring unit 55 acquires a resume point fromthe resume point monitoring unit 54 and stores it in the storage unit 53when the network state detecting unit 51 detects a network trouble.

[0049] The resume point reading unit 56 reads out the resume pointstored in the storage unit 53 when the network state detecting unit 51detects the network trouble.

[0050] The multimedia data acquiring unit 57 acquires from the storageunit 53 multimedia data from the resume point read out by the resumepoint reading unit 56 when the network state detecting unit 51 detectsthe network trouble.

[0051] The multimedia data transmitting unit 58 transmits the multimediadata acquired by the multimedia data acquiring unit 57 to the PC via thenetwork.

[0052] The operation of the recording/playback apparatus according tothe embodiment of the present invention will be explained with referenceto the flow chart of FIG. 5.

[0053] Assume that the recording/playback apparatus is in a time slipplayback state. That is, the recording/playback apparatus transmitsmultimedia data to the PC while recording input multimedia data.

[0054] In this case, if a network trouble in the network connected tothe PC is detected, a resume point upon network detection is acquired(S1 and S2). Transmission of multimedia data to the PC is stopped (timeslip playback is stopped), but recording of multimedia data continues(S3).

[0055]FIG. 6 is a view for explaining the concept of time slip playback.

[0056]FIG. 6 shows a resume point 61 representing the position of datawhich is being played back (transmitted to the PC) in the presence of amultimedia data file, and a recording point 62 representing a currentrecording position.

[0057] In the embodiment of the present invention, if a network troubleoccurs, the resume point is acquired but recording continues. Thus, therecording point 62 proceeds (recording continues).

[0058] Whether the network has recovered is checked (S4), and if Yes inS4, the resume point is read out (S5) and time slip playback is resumedfrom the resume point (S6). In other words, multimedia data from theresume point is transmitted to the PC. The PC plays back the multimediadata even after recovery of the network.

[0059] The recording/playback apparatus according to the embodiment ofthe present invention acquires a resume point upon occurrence of anetwork trouble while continuing recording. The recording/playbackapparatus can resume time slip playback from the acquired resume pointafter recovery of the network.

[0060] <Another Embodiment>

[0061] A recording/playback apparatus according to another embodiment ofthe present invention will be described.

[0062]FIG. 7 is a functional block diagram showing therecording/playback apparatus according to the embodiment of the presentinvention.

[0063] As shown in FIG. 7, the recording/playback apparatus according tothe embodiment of the present invention comprises a network statedetecting unit 71, multimedia data recording unit 72, storage unit 73,resume point monitoring unit 74, resume point acquiring unit 75, resumepoint reading unit 76, multimedia data acquiring unit 77, transmittingunit 78, and receiving unit 79.

[0064] The network state detecting unit 71 detects the network state ofa network connected to a PC. More specifically, the network statedetecting unit 71 detects a network trouble such as disconnection of thenetwork, or recovery of the network after occurrence of a networktrouble.

[0065] The multimedia data recording unit 72 stores in the storage unit73 multimedia data which is input to the recording/playback apparatusand compressed by an encoder.

[0066] The resume point monitoring unit 74 always monitors, ofmultimedia data stored in the storage unit 73, a resume pointrepresenting the position of a multimedia data portion which has beentransmitted to the PC. The resume point is expressed by the playbacktime from the header of a multimedia data file, the file size, or thelike.

[0067] The resume point acquiring unit 75 acquires a resume point fromthe resume point monitoring unit 74 and stores it in the storage unit 73when the network state detecting unit 71 detects a network trouble.

[0068] The resume point reading unit 76 reads out the resume pointstored in the storage unit 73 upon reception of a resume point readrequest from the PC.

[0069] When receiving a multimedia data acquisition request based on theresume point from the PC, the multimedia data acquiring unit 77acquires, from a storage unit 3 on the basis of the multimedia dataacquisition request, multimedia data from the resume point read out bythe resume point reading unit 76.

[0070] The transmitting unit 78 transmits to the PC the multimedia dataacquired by the multimedia data acquiring unit 77 and the resume pointread out by the resume point reading unit 76.

[0071] The receiving unit 79 outputs a multimedia data acquisitionrequest from the PC to the multimedia data acquiring unit 77, andoutputs a resume point read request from the PC to the resume pointreading unit 76.

[0072]FIG. 8 is a functional block diagram showing the PC.

[0073] As shown in FIG. 8, the PC serving as a terminal of therecording/playback apparatus according to the embodiment of the presentinvention comprises a network state detecting unit 81, resume pointrequesting unit 82, transmitting unit 83, receiving unit 84, multimediadata requesting unit 85, multimedia data acquiring unit 86, and playbackunit 87.

[0074] The network state detecting unit 81 detects recovery of a networkafter occurrence of a network trouble.

[0075] The resume point requesting unit 82 generates a resume point readrequest when the network state detecting unit 81 detects recovery of thenetwork.

[0076] The transmitting unit 83 outputs to the recording/playbackapparatus the resume point read request generated by the resume pointrequesting unit 82, and a multimedia data request output from themultimedia data requesting unit.

[0077] The receiving unit 84 outputs multimedia data received from therecording/playback apparatus to the multimedia data acquiring unit 86,and outputs a resume point to the multimedia data requesting unit 85.

[0078] Based on a resume point sent from the recording/playbackapparatus, the multimedia data requesting unit 85 generates a multimediadata request for acquiring multimedia data from the resume point.

[0079] The multimedia data acquiring unit 86 acquires multimedia datareceived from the recording/playback apparatus and outputs it to theplayback unit 87. The playback unit 87 plays back the multimedia dataoutput from the multimedia data acquiring unit 86.

[0080] The operation of a recording/playback system including therecording/playback apparatus according to the embodiment of the presentinvention will be explained with reference to FIG. 9.

[0081] Assume that the recording/playback apparatus is in a time slipplayback state. That is, the recording/playback apparatus transmitsmultimedia data to the PC while recording input multimedia data.

[0082] In this case, if a network trouble in the network connected tothe PC is detected, a resume point upon network detection is acquired(S11 and S12). Transmission of multimedia data to the PC is stopped(time slip playback is stopped), but recording of multimedia datacontinues (S13).

[0083] Whether the network has recovered is checked (S14), and if Yes inS14, the PC outputs a resume point read request to acquire a resumepoint from the recording/playback apparatus via the network (S15).

[0084] Based on the acquired resume point, the PC outputs to therecording/playback apparatus a multimedia data request for acquiringmultimedia data from a position represented by the resume point. The PCacquires multimedia data subsequent to the position represented by theacquired resume point from the recording/playback apparatus via thenetwork (S16). The PC plays back the acquired multimedia data (S17).

[0085] The recording/playback system according to the embodimentacquires a resume point on the PC side even if a network trouble occurs.The system can acquire multimedia data from the position represented bythe resume point, and continuously play back the multimedia data.

[0086] In the above-described embodiments, when a network troubleoccurs, playback stops while recording continues. A resume point isacquired, and multimedia data is played back from the positionrepresented by the resume point. Alternatively, playback may not stopbut suspend.

[0087] The present invention is not limited to the above-describedembodiments, and can be variously modified without departing from thespirit and scope of the invention in practical use. The respectiveembodiments can be combined as properly as possible. In this case, theeffects of the combination can be obtained. The embodiments includeinventions on various stages, and various inventions can be extracted byan appropriate combination of building components disclosed. Forexample, when an invention is extracted by omitting several buildingcomponents from all those described in the embodiments, the omission isproperly compensated for by a well-known technique in practicing theextracted invention.

[0088] As has been described in detail above, the present invention canprovide a recording/playback apparatus capable of performing time slipplayback even upon occurrence of a network trouble. The presentinvention can also provide an information processing apparatus andrecording/playback system using the above recording/playback apparatus.

What is claimed is:
 1. An apparatus which transmits multimedia data tobe played back to a network, comprising: means for, when a trouble ofthe network is detected, stopping transmission of the multimedia data;means for acquiring a point representing a position of the multimediadata obtained when transmission of the multimedia data is stopped; andmeans for retransmitting the multimedia data to the network from thepoint acquired by the acquiring means.
 2. An apparatus according toclaim 1, further comprising, means for storing the multimedia data in astorage device, and means for reading out the multimedia data from thestorage device and transmitting the readout multimedia data to thenetwork.
 3. An apparatus according to claim 1, further comprising, meansfor monitoring, of the multimedia data, the point representing aposition of a multimedia data portion which is transmitted by said meansfor transmitting.
 4. An apparatus according to claim 1, furthercomprising, means for detecting the trouble of the network based on astate of the network.
 5. An apparatus according to claim 2, wherein themeans for stopping stops transmission of the multimedia data whilestoring the multimedia data in said means for storing.
 6. An apparatuswhich transmits multimedia data to be played back to a network,comprising: means for transmitting the multimedia data to the network;means for, when a trouble of the network is detected, stoppingtransmission of the multimedia data; means for acquiring a pointrepresenting a position of the multimedia data obtained whentransmission of the multimedia data is stopped; means for transmittingthe point acquired by said acquiring means to the network on the basisof a point acquisition request; and means for transmitting themultimedia data to the network on the basis of a multimedia dataacquisition request in response to the transmitted point.
 7. Anapparatus according to claim 6, further comprising, means for storingthe multimedia data in a storage device, and means for reading out themultimedia data from the storage device.
 8. An apparatus according toclaim 6, further comprising, means for monitoring, of the multimediadata, the point representing a position of a multimedia data portionwhich is transmitted by said transmitting means.
 9. An apparatusaccording to claim 6, further comprising, means for detecting thetrouble of the network based on a state of the network.
 10. An apparatusaccording to claim 7, wherein the means for stopping the transmission ofthe multimedia data while storing the multimedia data in said means forstoring.
 11. An apparatus according to claim 7, which further comprisescompressing means for compressing the multimedia data, and in which saidmeans for storing stores the multimedia data compressed by saidcompressing means.
 12. An information processing apparatus whichreceives multimedia data to be played back via a network, and plays backthe received multimedia data, comprising: means for detecting a state ofthe network; means for, when recovery of the network is detected,acquiring a point representing a position of a multimedia data portiontransmitted to said information processing apparatus; means foracquiring via the network the multimedia data from the positionrepresented by the acquired point; and means for playing back theacquired multimedia data.
 13. An apparatus according to claim 12,wherein said playback means decompresses the multimedia data acquired,and plays back the decompressed multimedia data.
 14. Arecording/playback method in a recording/playback apparatus whichtransmits multimedia data to be played back to a network, comprising:stopping transmission of the multimedia data when a trouble of thenetwork is detected; acquiring a point representing a position of themultimedia data obtained when transmission of the multimedia data isstopped; and retransmitting the multimedia data to the network from thepoint acquired.
 15. A recording/playback method according to claim 14,further comprising, storing the multimedia data in a storage device, andreading out the multimedia data from the storage device and transmittingthe readout multimedia data to the network.
 16. A recording/playbackmethod according to claim 14, further comprising, monitoring, of themultimedia data, the point representing a position of a multimedia dataportion which is transmitted.
 17. A recording/playback method accordingto claim 14, further comprising, detecting the trouble of the networkbased on a state of the network.
 18. A recording/playback method in arecording/playback apparatus which transmits multimedia data to anetwork, comprising: transmitting the multimedia data to the network;stopping transmission of the multimedia data when a trouble of thenetwork is detected; acquiring a point representing a position of themultimedia data obtained when transmission of the multimedia data isstopped; transmitting the point acquired to the network on the basis ofa point acquisition request; and transmitting the multimedia data to thenetwork on the basis of a multimedia data acquisition request inresponse to the transmitted point.
 19. A recording/playback methodaccording to claim 18, further comprising, monitoring, of the multimediadata, the point representing a position of a multimedia data portionwhich is transmitted.
 20. A recording/playback method according to claim18, further comprising, detecting the trouble of the network based on astate of the network.